Friday’s IPO by Rocket Fuel (FUEL), which saw the shares spike from its $29 offering price to a high of $62.50 and a strong, $56.10 close, may mark a shift in enthusiasm around advertising-technology companies. This could signal opportunity for investors.

Rocket Fuel is a technology company that has developed an artificial-intelligence (AI) based automated, decision-making platform for online advertising. The company’s “programmatic” platform enables customers to buy online media in “real time” through digital advertising exchanges. It also allows real time targeting to get the right ad in front of the right person in real time. Based on Friday’s close, the Redwood City, California-based company has a market capitalization approaching $2 Billion. For the years ended December 31, 2010, 2011 and 2012, its revenues were $16.5 million, $44.7 million and $106.6 million, respectively, and for the six months ended June 30, 2012 and 2013, its revenues were $39.6 million and $92.6 million, respectively.

Executives on Rocket Fuel’s IPO road show successfully told the story about the effectiveness and scalability of their programmatic, real-time bidding (RTB) platform.Programmatic refers to buying and selling done on a real-time basis using data-driven rules and algorithms to automate the process of identifying and targeting relevant audiences. Platforms such as Rocket Fuel’s allow for advertising inventory to be bought and sold on an impression-by-impression basis. According to market research firm IDC, RTB is expanding faster than any other segment of the digital advertising industry, with total RTB sales increasing from approximately $3 billion in 2012 to approximately $14 billion in 2016.

According to market research firm eMarketer, the worldwide digital advertising market will exceed $118 Billion dollars this year, and is expected to surpass $163 Billion by 2016.

Other companies in the space include Tremor Video (TRMR), which went public in late June @ $10, stumbled nearly 40% shortly after its IPO, but has been on a tear since mid-August and traded north of $11 this past week before closing the week @ $9.80. YuMe (YUME), which is also based in Redwood City, CA, and went public in August @ $9/share, closed Friday @ $10.88, is also a video-centric ad-tech play. Tremor, which is headquartered in New York, has market cap is in the $500MM range and YuMe’s is roughly $350MM. Mobile ad network Millennial Media (MM), which went public in March 2012 at $13, doubled out of the gate and has dropped to under $8 today, which still represents a market cap north of $600MM. Millennial recently agreed to acquire JumpTap for over $200MM.

Some other growing companies in the space include PubMatic, Rubicon Project, and OpenX, but all three of these are privately-held. And NetShelter was acquired in May by Ziff Davis, which is a subsidiary of j2 Global (JCOM).

As this space continues to consolidate small companies with complimentary technology may become possible acquisition targets. One early-stage public company in this space that many people probably haven’t heard about is Mimvi, Inc. (MIMV.ob), which acquired Adaptive Media in July and announced this past week that it will take on that corporate name moving forward. Adaptive Media is a “multi-channel” Supply-Side Platform (SSP) for mobile, video and online display advertising. The Irvine, California-based company partners with mobile app developers, video content providers and website owners who have a supply of ad inventory and puts this inventory into its platform to be matched with advertisers. Adaptive Media is in the process of integrating Mimvi’s core discovery and recommendation technology into its systems to optimize ad performance. Adaptive Media released its audited financial results which included $613,347 in top-line revenues for the first six months of 2013. At only $.09/share, its market capitalization huddles around $10MM, which may offer investors a chance to get in on the ground floor.

Another ad company that has been in the news recently with its deal with Google (GOOG) is Hipcricket (HIPP.ob) and currently has a market cap of $72M. Hipcricket also just received an additional US patent 8539043 which is titled “System and method for adding targeted content in a web page”.

As witnessed by the Rocket Fuel IPO lift off on Friday the ad technology space is red hot. Some of the relatively new IPOs in the ad space have certainly benefited from the renewed interest in the space and well established companies are certainly worth watching as potential takeover candidates.

The following is a guest post by fellow investor mobile guru, whose interest lie within the mobile revolution, start-ups & IPO’s, and intellectual property.